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MG MGB Technical - Simple? wiring question.

I've read what I can about about the wiring harness on my '78 B. The problem I can't seem to beat is the lights on the passanger side won't work. I see that the commen wire is red however, I can't seem to locate the short. Has any of You,..had the same expirence?..and what can I do to over come this problem? Thanks in advance. Kev
Kevin Venable

Have you checked the ground for the light?
Derek Nicholson

Usually there is a problem with the grounding of the lights to the body, and at the harness connectors. Start by disassembling and cleaning everything and go from there. You don't specify which lights aren't working, so without more details its difficult to pinpoint a solution. :-(


Jeff Schlemmer

Hi, Thanks for the replies. None of the lights on the right hand side of the car are working,..IE: headlight, except for high beam when stalk is pulled back,..parking, side running light (both front and rear) tail lights and tag light on right side. The ground theory sounds interesting,..Is there a source with maybe a diagram of ground points for our LBCs?
Kevin Venable

See if you are getting power to the lights...put meter or test light on wire at bulb and turn switch on and see if you light up the test light. Just ground the test light somewhere nearby. If power's good then probably is the ground issue and you can work backward to see where other wire to light is grounded. Is great idea to clean each connector up as you go anyway and re-assemble with dielectric grease.
My test light is just a similar sized 12 v bulb socket/and bulb from auto store with alligator clips on the wires. Very handy.
J.T. Bamford

Kev,

How does fault No. 6 on the electrical site compare to your problem?
http://www.mgcars.org.uk/electrical/light_faults.html

Doug
D. Cook

Kev,

I meant my other left. Fault No. 5.

Doug
D. Cook

Once you identify your problem (does sound like ground), don't forget to apply dialectric grease to the wires when you're reassembling them. If the factory had done that with those Lucas connector sleeves - well, better not to torture ourselves.
Adam Birnbaum

Fault 5 is it exactly..Thanks.
Kevin Venable

There is a ground wire on the inner passenger side fender, follow your harness forward until you just get to the light and there it should be. There is also one under the grill, near your horn. Their is so many of those pull-apart connectors that they can come apart with a slight tug.
I have just sorted all of this out my self. A wiring diagram, flashlight, ohms meter or test light is a must when dealing with any wiring issues. These cars are so old and so many people have done things to them over the years that many times it is just a ground disconnected, so I would't worry at all, just have patience.
Neil Campbell

This thread was discussed between 11/04/2004 and 17/04/2004

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